IS32LT3151: Linear LED Driver with PWM Dimming and Thermal Shunt

These 450mA current-source linear LED drivers are designed for automotive lighting applications, including tail/brake light combinations. Using a high-side output topology, they enable LED output strings to share a common ground—reducing wiring complexity and simplifying harness design. For high-power applications, optional thermal shunt or sharing resistors can be added to help offload heat from the driver, minimizing thermal stress when driving high-brightness LEDs. The family also supports key features such as analog dimming, single-LED short detection, and compliance with ASIL-B safety requirements.

All devices offer open/short fault detection at the LED string level and can be configured for “one-fail-all-OFF” behavior when a fault occurs. Faults are reported through a shared open-drain FAULTB pin, giving system designers flexibility in defining fault-response strategies. Each driver is AEC-Q100 qualified for reliable operation in harsh automotive environments, with the IS32LT3151C/D meeting ISO 26262 ASIL-B functional safety standards, while the IS32LT3151A/B do not.

Key features

• Single channel at 450mA
• Thermal Shunt resistors to lower device thermal stress
• Analog dimming and Single LED short detection (A/C version only)
• ISO 26262 ASIL-B support (C/D version only)

Applications

• Center high mount stop lights (CHMSL)
• Position, parking, or side lights
• Reverse backup lights
• Daytime running lights (DRL)